It's important to recognise that when we talk about something like protein or a vitamin that we are focusing in on a single nutrient. Macronutrients (protein, carbohydrate, fat) and micronutrients (vitamin A, C, D etc.) have important roles in the body, but these roles are part of the hugely complex system which is the human body functioning. There are thousands upon thousands of processes and interlinking interactions between the nutrients we get from food. 

When it comes to food, our health, and survival, we don't eat single nutrients, we eat food. When reading and learning about a specific nutrient it's important to keep that principle in your head. It's also important to note that while we know a lot, we don't yet know every single thing about how nutrients interact with each other and the implications on our health.

Here's an example of what I mean using protein as our 'single nutrient' and an egg as our 'food'.

A person may learn that protein helps in building muscle (it does a lot more than that) and decide they want to focus on their protein intake. They see that eggs are a good source of protein and include them in their diet. But eggs also contain energy and a host of other nutrients (fat, vitamins, minerals) as you can see below.

There is nothing wrong with doing this. People have goals and they look for information. Eggs are nutrient dense, a good source of protein and many other important vitamins and minerals.

But what about the cholesterol? Will it negatively affect my health? (dietary cholesterol intake doesn't affect cholesterol levels to the detriment of health in healthy individuals). You choose to eat eggs for one thing, but there are other things to consider.

Also, you'll probably have the eggs as part of a larger meal. Other food products which contain other nutrients are then involved. You may have the meal with someone else in a social setting. Reading about nutrients is great, but it can almost cause a reductionist way of thinking in terms of food and how we manage our nutrition every day. Food is more than single nutrients and it is a big part of culture and how we socialise.

While something you learn may focus on a single thing remember that there are many things. You don't just eat  an egg and get protein, you eat an egg and get some protein but also many other things.

A written guideline or recommendation and translating it in to practice are two very different things.

A single nutrient may play an important role in something specific (protein & muscle building/retention), but we rely on many nutrients to survive and to thrive. Protein isn't the only variable in building muscle either, to build muscle you will also need to lift weights (the primary factor), to get enough sleep, to recover properly and to do it over long enough periods of time. 

If you read that walking is good for health remember that walking is one thing but there are many things involved in good health. 

Always think about the broader picture.

When trying to eat and live well for your health or training goals you'll understand there are many puzzle pieces, not just one, and you'll be able to see where each one fits.

Now, when we look at protein, we will look at it in terms of helping with weight loss, managing weight, muscle building and retention - but we now know there's a lot more going on than this in terms of it's role in the body and in terms of looking after our health.

We'll look at protein through our lens, but we will also keep the bigger picture in mind and discuss it along the way.

Nutrient guidelines are quite simple, but food is complex.


Protein is made up of amino acids. Think of them as building blocks. When we eat food the protein gets digested and broken down into all these building blocks and they go off and get involved in their different jobs in the body of which there are MANY.

Some building blocks can actually be made from within the body. Yes, the human body makes them itself. Amazing! But some we must get through food, and we do, so don't worry. It's just interesting to know.

Different sources of protein have different amounts of the building blocks and certain building blocks can be missing or present. Just like food is different in colour, texture and taste, it is different in composition and amounts of protein. The make up of the protein in an egg is different to the protein in porridge oats and the protein in chickpeas is different again. 

Different food, different building blocks, different amounts of building blocks.

It's helpful to understand this when we think about what is the best source of protein. You know they have a structure of building blocks, these blocks do certain things in the body and some sources are superior than others.

This is where we discuss the sources.

Plant vs Animal Protein.

There are two types of protein source, plant based protein and animal based protein. Plant based sources are just that, nuts, seeds, grains and basically anything that is grown or plant based. Here are some examples below.

When we look at animal sources we see that it is a combination of animal product and products which come from animals such as egg, cheese and milk (dairy). The image below shows some examples.

Protein sources can actually be rated by the amount of amino acids (building blocks) they have, and their ability to be digested fully. Some foods have better digestibility than others, we can efficiently take and use all the nutrients, while other foods are less efficiently digested.

If something has all the important building blocks and is digested well it is rated highly. Those with missing building blocks and which digest less well are rated lower. The PDCASS scale does exactly this and can be seen below.

When we look at plant versus animal sources of protein we see that animal protein scores better on this scale. Animal protein has more building blocks and they are more efficiently digested by the body.

When it comes to something like muscle building and performance then we can see that animal sources are superior to plant based protein for that purpose.

Does this mean we should only eat animal sources of protein? No. It doesn't mean they are superior for everything.

Remember that protein is one component of food, we need many other nutrients and if we were to only eat animal products because they score well in terms of one goal we'd end up missing out on other important nutrients from plant based foods for all the other health based goals. Plant based foods are nutrient dense, they contain fibre and many other vitamins, minerals and phytonutrients (nutrients exclusive to plants) which are important for health.

Are animal sources better than plants? For something like muscle building and retention yes - but we still want a varied diet and a mix of nutrients so going 'all animal' or 'all plant' isn't advisable.

What we can do though is take this information and try and make it work for us and our goals. 

Managing Your Weight & Muscle Building.

In terms of what we want to achieve it is generally to build muscle and to manage our weight. This may be lose weight, it may be maintain weight, or someone might want to put on weight. I'm going to focus on where protein fits in with losing weight, maintaining weight and it's importance in relation to our muscle mass.

When it comes to our weight we know that energy balance is king and that to lose weight we have to stick to a calorie deficit long enough for this to happen. Protein is satiating, it helps us feel fuller for longer which is great when trying to lose weight. Feeling full after a meal is important when you're in a calorie deficit.

What helps me frame this in my own head is to look at what is labelled 'junk food'. You'll notice the protein content is always quite low. Generally, when the protein content of a product is low and it's a processed food it usually tastes pretty good and it is not satiating. These products won't keep you full and it's much easier to over consume and wipe out a calorie deficit.

When you're trying to maintain your weight constant over consumption can result in a calorie surplus and we put on weight. Add to that they don't really have much nutrient value for health either and you see why 'junk food' isn't great for your weight and where a protein based meal is a superior choice.

It doesn't mean you can never eat these products. They shouldn't be deemed as bad or terrible. What if someone is underweight, recovering from an illness and urgently needs to put on weight for their health? 'Easy to eat' calories play a role there. Remember that context is always important.

We don't need to eat 100% 'clean' foods to lose weight or be healthy. We can fit in nice things and that's actually important as outright restriction can be terrible, but eating them all the time is not conducive to managing your weight. It's important to be able to identify why certain products may or may not support your goals or a goal this is not yours.

When you compare these lower protein products to more nutrient dense, fresher foods as seen in the images below you can see these fresher foods are high in protein, have a host of other nutrients AND will keep you full whether it be plant or animal sources.

Animal sources score well in terms of building blocks and digestibility of nutrients, but plant sources are a source of fibre which plays a big role in gut health and also helps keep us feeling full PLUS man other nutrients.

Having a source of protein in a meal, whether it be plant based, animal based, or both, is a great template to have. Having a source of protein in a meal and then adding more plant based foods after that is an EVEN BETTER template. Protein + fibre = win.

It's also important to remember that when you see graphics like the ones above it may make things look unappealing. These are purely a guide on sources of protein, it's up to us to find and make meals based on these guidelines that we love eating and know support our goals. This is why I think it's important to cook and explore recipes. It has never been easier to do this with access to recipes labelled with the protein and other nutrient contents, the calorie content and all the ingredients and instructions. 

This is why meal plans given to people will never work long term. You need to learn how to prepare food you like that supports your goals.

It's also a good example of nutrients versus actual food or mixed meals. We eat food, not single nutrients as mentioned at the beginning. When you think of your protein target for the day don't just think of a number, think of the delicious food you get to eat!

Good sources of protein and plant based foods help us feel full and are great sources of nutrients too.

But what about muscle building? Let's take a look.

Protein & Muscle.

Muscle mass is incredibly important. Your skeletal muscle is what enables you to move and perform physical tasks from something as simple as brushing your teeth to more complex tasks like running after a bus and having to jump some hurdles on the way. 

If you take two versions of the same person, the version who is active, strong, mobile, and has more muscle mass will have a higher quality of life and less chance of suffering from chronic disease compared to the version who is sedentary with less muscle mass.

There is a misconception that if someone starts to lift weights they will become bulky. This is a misconception as people associate lifting weights with body builders who have long graced magazines and TV screens. Steroid and steroid type substances that enhance growth are used regularly and these substances vastly speed up the muscle building process and pushes growth beyond normal genetic limits. 

Muscle mass and strength is protective. If I could advise you one thing it is to associate it with quality of life, longevity and the body composition you always wanted. It takes a huge amount of hard work over time to build muscle. The body you want is gained through lifting weights and looking after your nutrition for years, not days. While the term 'bulky' is subjective, I would argue you will never, ever get even close to being bulky.

When you read the following on muscle and protein banish the prospect of getting 'too bulky' from your thoughts. Quality of life, longevity and improved body composition. There are no downsides to training and eating to support muscle mass.

When we look to build muscle it's very important to note that training and lifting weights is the main driver. Consuming protein doesn't cause muscle growth, it supports it but remember you won't build muscle unless you train.

Getting in to the specifics of training and muscle growth is an article in itself so we'll skip that. A good summary is that you need to train a certain amount of times per week in an ideal situation, and you need to train the muscle groups a certain amount of times too. The law of diminishing returns applies here. When you start out you'll make great progress with strength and muscle, but that diminishes over time. Don't let that bother you.

Remember all the benefits of training, when you've been doing it for years your health, promoting it, and maintaining your strength should be the primary goal. That's not to say progress will stop, there are so many things to improve on.

The amount of muscle mass you have is the result of something called muscle protein synthesis (MPS). Your muscle tissue is constantly in a state of turnover throughout the day. It builds up and breaks down.

Muscle protein synthesis is the building part, muscle protein breakdown is the breaking down part. This is perfectly normal and just how the body works. I try to imagine a 3D printer printing something. It builds up, but then at a certain point this must stop and reverses the print back down.

This process is constant.

The net difference between synthesis and breakdown is your muscle mass. You can't do a whole lot to change the breakdown process, instead we focus on the synthesis part.

Weight training stimulates synthesis to a higher degree than normal and consuming enough protein augments this. It's very subtle though, it takes many training sessions and consuming adequate protein to see and feel change. We're talking months and years as opposed to days and weeks. This is why it's so important people banish the thought of getting bulky, it really is not going to happen and then you're also missing out on so many health and wellness benefits by putting off lifting.

You'll see from the picture below that lifting (one session) will boost MPS and the right protein intake really helps squeeze out as much progress as possible. The net outcome over time is more synthesis than breakdown so you put on more muscle.

When someone is incapacitated from a fall or bed ridden in some way and muscle mass isn't used or stimulated you can see from the picture below that synthesis is very low. The net difference is more breakdown so the person LOSES muscle mass which is NEVER, EVER what we want to happen because it is so valuable to our well being. Forget about how we look, muscle mass is protective and extremely important to our health.

You can also see how someone who is sedentary and doesn't train would have low muscle mass. Some people are blessed with good genes and may have decent muscle mass without doing much but that's rare. Most of us need to be active.

The last of my amazing diagrams will highlight where the 'i don't want to get bulky' school of thought comes from. Anabolic steroid use rips up the rule book and flings it out the window. It helps someone put on HUGE amounts of muscle mass that just wouldn't be possible without taking it. We all have a genetic potential for putting on muscle and these drugs help go WAY beyond that. Years and years of progress can be made in weeks or months. The diagram below is for illustrative purposes only, it's not the exact or main reason behind how steroid use boosts muscle growth, it's just to demonstrate in a way which is relevant to what I've already discussed here relating to muscle growth.

Many people associate lifting weights with guys (or girls) they've seen on TV or in magazines who use these substances but aren't open about it. 'If I lift weights I'll look like that person, I really don't want to do that'. It's actually pretty sad because so many people miss the huge health benefits and body composition changes they'd love because someone who cheats the laws of muscle growth puts them off touching weights.

In summary we now know that our muscle builds up and breaks down naturally throughout the day, every day. When we train with weights regularly it promotes the synthesis part and a net greater outcome of this versus muscle breakdown is what leads to muscle gain. This adds to health, well-being and helps you look your best.

How much protein should we take then to augment this process? We'll look at that next.

Recommended Daily Intake.

Nutrient Intake Across The Life Cycle.

Athlete vs Normal Person.

Timing Of Intake.

Protein & Healthy Ageing.

Protein Intake For Children.

'High Protein' Labelled Foods.

Now it's time to talk about how much per day and why.

There are government guidelines on protein intake and we will look at these versus some of the more recent research. The context of what a person is trying to achieve is important here too. I say this because certain guidelines are given for the general public as a guide for healthful living. Once we start adding exercise in the guidelines change a little and we delve deeper.

Thanks to research which has mainly come from the area of sports science we can look more closely at the amount of protein we need in a day if we train and want to squeeze the most out of our hard work. We are lucky enough to have had some amazing research come out recently relating to protein intake and healthy ageing also, so knowing how much protein to eat to support health as we grow older is something we know more and more about.

You'll see there is no single answer on intake for everyone, but there are some great guidelines we can follow which  can be tweaked to our preferences too.